Solar panels are not zero maintenance, but they are low maintenance. A bi-annual washing is recommended for locations which have high pollen, and/or near a farm. The solar panel modules are exceptionally reliable and very rarely fail. If something on your roof is going to fail, it is a power electric device that is manufactured by the inverter company. Typically, the manufacturer will pay the installation company for the replacement of those devices for a period of time.
Taking care of roof-mounted panels is more difficult since it involves climbing the roof. Rooftop safety is not always guaranteed. In fact, installation companies always face a rooftop safety risk when performing their job. Therefore, you should call in a professional to do the maintenance for you.
If you choose to go with a ground-mount system, they are literally at ground level, so cleaning and taking care of them is much easier than roof-based arrays. Nonetheless, they require more frequent maintenance due to their proximity to dirt and snow.
Maintaining a solar panel system is not something that should be a huge concern. They sit on the roof or on the ground. They are producing electricity on a regular basis for you. And your home is now sourcing its power from a sustainable, renewable energy source!